Adds this common format to vkms.
This commit also adds new helper macros to deal with fixed-point arithmetic.
It was done to improve the precision of the conversion to ARGB16161616 since the "conversion ratio" is not an integer.
Signed-off-by: Igor Torrente igormtorrente@gmail.com --- drivers/gpu/drm/vkms/vkms_composer.c | 4 ++ drivers/gpu/drm/vkms/vkms_formats.h | 72 +++++++++++++++++++++++++++ drivers/gpu/drm/vkms/vkms_plane.c | 6 ++- drivers/gpu/drm/vkms/vkms_writeback.c | 3 +- 4 files changed, 82 insertions(+), 3 deletions(-)
diff --git a/drivers/gpu/drm/vkms/vkms_composer.c b/drivers/gpu/drm/vkms/vkms_composer.c index f16fcfc88cea..57ec82839a89 100644 --- a/drivers/gpu/drm/vkms/vkms_composer.c +++ b/drivers/gpu/drm/vkms/vkms_composer.c @@ -166,6 +166,8 @@ static void ((*get_line_fmt_transform_function(u32 format)) return &get_ARGB16161616; else if (format == DRM_FORMAT_XRGB16161616) return &XRGB16161616_to_ARGB16161616; + else if (format == DRM_FORMAT_RGB565) + return &RGB565_to_ARGB16161616; else return &XRGB8888_to_ARGB16161616; } @@ -179,6 +181,8 @@ static void ((*get_output_line_function(u32 format)) return &convert_to_ARGB16161616; else if (format == DRM_FORMAT_XRGB16161616) return &convert_to_XRGB16161616; + else if (format == DRM_FORMAT_RGB565) + return &convert_to_RGB565; else return &convert_to_XRGB8888; } diff --git a/drivers/gpu/drm/vkms/vkms_formats.h b/drivers/gpu/drm/vkms/vkms_formats.h index aa433edd00bd..1e2db1a844aa 100644 --- a/drivers/gpu/drm/vkms/vkms_formats.h +++ b/drivers/gpu/drm/vkms/vkms_formats.h @@ -8,6 +8,26 @@ #define pixel_offset(composer, x, y) \ ((composer)->offset + ((y) * (composer)->pitch) + ((x) * (composer)->cpp))
+/* + * FP stands for _Fixed Point_ and **not** _Float Point_ + * LF stands for Long Float (i.e. double) + * The following macros help doing fixed point arithmetic. + */ +/* + * With FP scale 15 we have 17 and 15 bits of integer and fractional parts + * respectively. + * | 0000 0000 0000 0000 0.000 0000 0000 0000 | + * 31 0 + */ +#define FP_SCALE 15 + +#define LF_TO_FP(a) ((a) * (u64)(1 << FP_SCALE)) +#define INT_TO_FP(a) ((a) << FP_SCALE) +#define FP_MUL(a, b) ((s32)(((s64)(a) * (b)) >> FP_SCALE)) +#define FP_DIV(a, b) ((s32)(((s64)(a) << FP_SCALE) / (b))) +/* This macro converts a fixed point number to int, and round half up it */ +#define FP_TO_INT_ROUND_UP(a) (((a) + (1 << (FP_SCALE - 1))) >> FP_SCALE) + /* * packed_pixels_addr - Get the pointer to pixel of a given pair of coordinates * @@ -102,6 +122,35 @@ static void XRGB16161616_to_ARGB16161616(void *pixels_addr, int length, } }
+static void RGB565_to_ARGB16161616(void *pixels_addr, int length, + u64 *line_buffer) +{ + __le16 *src_pixels = pixels_addr; + int i; + + for (i = 0; i < length; i++) { + u16 rgb_565 = le16_to_cpu(*src_pixels); + int fp_r = INT_TO_FP((rgb_565 >> 11) & 0x1f); + int fp_g = INT_TO_FP((rgb_565 >> 5) & 0x3f); + int fp_b = INT_TO_FP(rgb_565 & 0x1f); + + /* + * The magic constants is the "conversion ratio" and is calculated + * dividing 65535(2^16 - 1) by 31(2^5 -1) and 63(2^6 - 1) respectively. + */ + int fp_rb_ratio = LF_TO_FP(2114.032258065); + int fp_g_ratio = LF_TO_FP(1040.238095238); + + u64 r = FP_TO_INT_ROUND_UP(FP_MUL(fp_r, fp_rb_ratio)); + u64 g = FP_TO_INT_ROUND_UP(FP_MUL(fp_g, fp_g_ratio)); + u64 b = FP_TO_INT_ROUND_UP(FP_MUL(fp_b, fp_rb_ratio)); + + line_buffer[i] = 0xffffllu << 48 | r << 32 | g << 16 | b; + + src_pixels++; + } +} + /* * The following functions are used as blend operations. But unlike the * `alpha_blend`, these functions take an ARGB16161616 pixel from the @@ -177,4 +226,27 @@ static void convert_to_XRGB16161616(void *pixels_addr, int length, } }
+static void convert_to_RGB565(void *pixels_addr, int length, + u64 *line_buffer) +{ + __le16 *dst_pixels = pixels_addr; + int i; + + for (i = 0; i < length; i++) { + int fp_r = INT_TO_FP((line_buffer[i] >> 32) & 0xffff); + int fp_g = INT_TO_FP((line_buffer[i] >> 16) & 0xffff); + int fp_b = INT_TO_FP(line_buffer[i] & 0xffffllu); + + int fp_rb_ratio = LF_TO_FP(2114.032258065); + int fp_g_ratio = LF_TO_FP(1040.238095238); + + u16 r = FP_TO_INT_ROUND_UP(FP_DIV(fp_r, fp_rb_ratio)); + u16 g = FP_TO_INT_ROUND_UP(FP_DIV(fp_g, fp_g_ratio)); + u16 b = FP_TO_INT_ROUND_UP(FP_DIV(fp_b, fp_rb_ratio)); + + *dst_pixels = cpu_to_le16(r << 11 | g << 5 | b); + dst_pixels++; + } +} + #endif /* _VKMS_FORMATS_H_ */ diff --git a/drivers/gpu/drm/vkms/vkms_plane.c b/drivers/gpu/drm/vkms/vkms_plane.c index 516e48b38806..de250808aa39 100644 --- a/drivers/gpu/drm/vkms/vkms_plane.c +++ b/drivers/gpu/drm/vkms/vkms_plane.c @@ -13,14 +13,16 @@
static const u32 vkms_formats[] = { DRM_FORMAT_XRGB8888, - DRM_FORMAT_XRGB16161616 + DRM_FORMAT_XRGB16161616, + DRM_FORMAT_RGB565 };
static const u32 vkms_plane_formats[] = { DRM_FORMAT_ARGB8888, DRM_FORMAT_XRGB8888, DRM_FORMAT_XRGB16161616, - DRM_FORMAT_ARGB16161616 + DRM_FORMAT_ARGB16161616, + DRM_FORMAT_RGB565 };
static struct drm_plane_state * diff --git a/drivers/gpu/drm/vkms/vkms_writeback.c b/drivers/gpu/drm/vkms/vkms_writeback.c index 0f7bb77f981e..11eb1be5a0fc 100644 --- a/drivers/gpu/drm/vkms/vkms_writeback.c +++ b/drivers/gpu/drm/vkms/vkms_writeback.c @@ -15,7 +15,8 @@ static const u32 vkms_wb_formats[] = { DRM_FORMAT_XRGB8888, DRM_FORMAT_XRGB16161616, - DRM_FORMAT_ARGB16161616 + DRM_FORMAT_ARGB16161616, + DRM_FORMAT_RGB565 };
static const struct drm_connector_funcs vkms_wb_connector_funcs = {